Flexible multiplexing of users with difference requirements in a 5g frame structure

ABSTRACT

A communications device configured to communicate in a wireless system having a wireless access interface providing communications resources arranged in time divided units of a host radio access technology, RAT, frequency bandwidth, the time divided units and the host RAT interface frequency bandwidth being arranged into one or more virtual RAT interfaces. The communications device configured to receive the signals transmitted via one of the virtual RAT interfaces in accordance with different communications parameters from the host RAT interface providing different characteristics for communicating data represented by the signals with respect to a characteristic of signals transmitted according to communications parameters in the communications resources of the host RAT interface.

TECHNICAL FIELD OF THE DISCLOSURE

The present disclosure relates to communications devices configured totransmit data via a wireless communications network and to receive datafrom a wireless communications network, wherein the wirelesscommunications network has been configured to provide wirelesscommunications in accordance with different communications parameters.In some embodiments the wireless access interface is configured toprovide support for communications from different types of devices. Thepresent invention also relates to methods of communicating usingcommunications devices, wireless communications network, infrastructureequipment and methods.

BACKGROUND OF THE DISCLOSURE

Third and fourth generation mobile telecommunication systems, such asthose based on the 3GPP defined UMTS and Long Term Evolution (LTE)architecture are able to support more sophisticated services than simplevoice and messaging services offered by previous generations of mobiletelecommunication systems. For example, with the improved radiointerface and enhanced data rates provided by LTE systems, a user isable to enjoy high data rate applications such as mobile video streamingand mobile video conferencing that would previously only have beenavailable via a fixed line data connection. The demand to deploy thirdand fourth generation networks is therefore strong and the coverage areaof these networks, i.e. geographic locations where access to thenetworks is possible, is expected to increase rapidly. However, whilstfourth generation networks can support communications at high data rateand low latencies from devices such as smart phones and tabletcomputers, it is expected that future wireless communications networkswill need to support communications to and from a much wider range ofdevices, including reduced complexity devices, machine typecommunication devices, devices which require little or no mobility, highresolution video displays and virtual reality headsets. As such,supporting such a wide range of communications devices can represent atechnical challenge for a wireless communications network.

SUMMARY OF THE DISCLOSURE

According to a first aspect of the present disclosure there is provideda communications device for transmitting data to or receiving data froma wireless communications network. The communications device comprises atransmitter configured to transmit signals to one or more infrastructureequipment of the wireless communications network via a wireless accessinterface, a receiver configured to receive signals from one or more ofthe infrastructure equipment of the wireless communications network viathe wireless access interface, and a controller. The controller isconfigured to control the transmitter and the receiver to transmit thesignals to and to receive the signals from the infrastructure equipmentvia the wireless access interface. The wireless access interfaceprovides communications resources arranged in time divided units of ahost radio access technology (RAT) interface frequency bandwidth, thetime divided units and the host RAT interface frequency bandwidth beingarranged into one or more virtual RAT interfaces. The receiver isconfigured to receive the signals transmitted via one of the virtual RATinterfaces in accordance with different communications parameters fromthe host RAT interface providing different characteristics forcommunicating data represented by the signals with respect to acharacteristic of signals transmitted according to communicationsparameters in the communications resources of the host RAT interface.

Embodiments of the present technique can therefore provide a wirelessaccess interface which is configured with one or more virtual radioaccess technology (RAT) interfaces within a host RAT interface of awireless communications network, which can support different types ofcommunications devices.

Embodiments of the present technique can provide an arrangement in whicha wireless access interface provided by a host mobile communicationsnetwork is configured to allocate those physical communicationsresources to provide different radio access techniques to differenttypes of devices. According to the present technique, a communicationsnetwork configures predetermined physical resources which may beregarded as virtual RAT interfaces to provide different communicationsparameters for different types of communications for different devices.Accordingly, a heterogeneous arrangement is provided for communicationsresources available with any host system which can be more applicable tosome devices, not others. As such, embodiments of the present techniquecan be arranged to provide parameterisation of radio resources accordingto service requirements, while sharing the same physical resources, aswell as flexibility in the network configurations, allowing for near orsubstantially optimised parameterisation depending on the service,device, and network types.

Various further aspects and embodiments of the disclosure are providedin the appended claims, including but not limited to, a communicationsdevice, infrastructure equipment, mobile communications system and amethod of communicating.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the present disclosure will now be described by way ofexample only with reference to the accompanying drawings in which likeparts are provided with corresponding reference numerals and in which:

FIG. 1 provides a schematic representation of communications systemwhich provides wireless data communications to different types ofcommunications devices using different types of infrastructure of amobile communications network;

FIG. 2 provides a schematic diagram illustrating an example of aconventional mobile communications system;

FIG. 3 provides a schematic diagram of a structure of a downlink of awireless access interface of a mobile communications system operatingaccording to an LTE standard;

FIG. 4 provides a schematic diagram of an uplink of a wireless accessinterface of a mobile communications system operating according to anLTE standard;

FIG. 5 provides a schematic diagram illustrating an example of an LTEdownlink wireless access interface, which includes a two examplesub-frames illustration of a previously proposed control channelarrangement;

FIG. 6 provides a schematic diagram illustrating an example of an LTEdownlink wireless access interface, which includes a previously proposedT-shaped virtual carrier in which resource allocation messages forallocating resources of the virtual carrier are transmitted within ahost control channel;

FIG. 7 provides a schematic diagram illustrating an example embodimentof the present technique in which a virtual sub-frame is formed fromfour sub-frames of a host wireless access interface;

FIG. 8 provides a schematic diagram illustrating an example embodimentof the present technique in which an LTE downlink radio sub-frame isdivided into an integer number of virtual sub-frames;

FIG. 9 is a schematic representation of a configuration of a hostwireless access interface in accordance with an LTE Standard includingwithin separate sections of the wireless access interface two differentvirtual RAT interfaces providing different communications parameters forserving different communications needs of different types of mobilecommunications devices; and

FIG. 10 is a schematic representation of another configuration of a hostwireless access interface in accordance with an LTE Standard includingwithin separate sections of the wireless access interface two differentvirtual RAT interfaces providing different communications parameters forserving different communications needs of different types of mobilecommunications devices.

DESCRIPTION OF EXAMPLE EMBODIMENTS Development of WirelessCommunications Networks

As explained above, wireless communications networks continue to evolveto meet more diverse requirements for different types of communicationsdevices. Whilst third and fourth generation systems have been arrangedto increase a data communications bandwidth for communications devices,it has been recognised that not all types of devices require high datarates. The 3GPP will start standardisation of a new 5G radio accesstechnology within the next few years. The aim of 5G is not only mobileconnectivity for people, but to provide ubiquitous connectivity for anytype of device and any type of application that would benefit from beingconnected. Many requirements and use-cases are still being discussed,these include:

-   -   Low latency transmission of data    -   Very high data rates    -   Millimetre wave spectrum    -   High density of network nodes providing small cells and relays    -   Large system capacity    -   Massive number of devices (e.g. MTC devices)    -   High reliability especially for mission critical devices such as        vehicle safety.    -   Low device cost and energy consumption    -   Flexible spectrum usage    -   Flexible mobility, catering for highly mobile devices as well as        devices which will be static.

A more comprehensive summary of requirements and use-cases may beprovided from [2] and [3].

FIG. 1 provides an example illustration of a future mobilecommunications system in which a plurality of different types of devicesis used. As shown in FIG. 1, a first base station 1 may be provided to alarge cell or macro cell in which the transmission of the signals isover several kilometres. However the system may also supporttransmission via a very small cell such as transmitted by a secondinfrastructure equipment 2 which transmits and receives signals over adistance of hundreds of metres thereby forming a so called “Pico” cell.In contrast a third type of infrastructure equipment 4 may transmit andreceive signals over a distance of tens of metres and therefore can beused to form a so called “Femto” cell.

Also shown in FIG. 1, different types of communications devices may beused to transmit and receive signals via the different types ofinfrastructure equipment 1, 2, 4 and the communication of data may beadapted in accordance with the different types of infrastructureequipment using different communications parameters. It is expected thatin the future many types of devices may communicate via a mobilecommunications system. Conventionally a mobile communications device maybe configured to communicate data to and from a mobile communicationsnetwork via the available communication resources of the network.Typically the wireless access system is configured to provide thehighest data rates to devices such as smart phones 6. However in thefuture a so called “internet of things” may be provided in which lowpower machine type communications devices transmit and receive data atvery low power, low bandwidth and may have a low complexity. An exampleof such a machine type communication device 8 may communicate via a Picocell 2. In contrast a very high data rate and a low mobility may becharacteristic of communications with, for example, a television 10which may be communicating via a Pico cell. Similarly a very high datarate and low latency may be required by a virtual reality headset 12.

As will be appreciated from the example shown in FIG. 1 there maytherefore be a plurality of different types of devices with differentdata rate and latency requirements for the transmitted data.Accordingly, the embodiments of the present technique can provide anarrangement in which available physical resources of a wireless accessinterface are subdivided in frequency and time into different portions,each portion being arranged so that data may be represented as differenttypes of signal waveforms within those physical resources so that thetransmission of the data within those physical resources is matched tothe type of application for which those mobile devices are configured.

As will be appreciated therefore there is a requirement to provide awireless communications network with a wireless access interface whichcan cater for and support communications of a variety of differenttypes. The problem is how to enable different types of communicationsdevices with completely different requirements such as high or low datarate, different latency requirements, different priorities such as powerconsumption vs. throughput, etc, and how to accommodate these differenttypes of device and service as well as different types of network nodewithin a single radio interface. Furthermore it is expected that“network slicing” will be required, which means that different serviceproviders (operators) may be able to share the same infrastructureequipment while serving different types of device or providing differentquality of service.

The present technique provides an arrangement for allowing data to becommunicated with different communications parameters and differenttypes of communications to be supported for different applications anddevices via a wireless access interface with a common framework.According to the present technique therefore the communicationsresources of the host RAT interface are configured differently accordingto the application to which they are directed. In one example, the hostcommunications interface may be configured in accordance with a 3GPPdefined Long Term Evolution (LTE) standard. As such in order toappreciate advantages and aspects provided by embodiments of the presenttechnique a wireless communications system configured in accordance withthe LTE standard will first be described.

Conventional LTE Network

FIG. 2 provides a schematic diagram illustrating some basicfunctionality of a mobile telecommunications network/system operating inaccordance with LTE principles. Various elements of FIG. 2 and theirrespective modes of operation are well-known and defined in the relevantstandards administered by the 3GPP® body, and also described in manybooks on the subject, for example, Holma H. and Toskala A [1]. It willbe appreciated that operational aspects of the telecommunicationsnetwork which are not specifically described below may be implemented inaccordance with any known techniques, for example according to therelevant standards.

The mobile telecommunications system, where the system shown in FIG. 2includes infrastructure equipment comprising base stations 101 which areconnected to a core network 102, which operates in accordance with aconventional arrangement which will be understood by those acquaintedwith communications technology. The infrastructure equipment 101 mayalso be referred to as a base station, network element, enhanced NodeB(eNodeB) or a coordinating entity for example, and provides a wirelessaccess interface to the one or more communications devices within acoverage area or cell represented by a broken line 103. One or moremobile communications devices 104 may communicate data via thetransmission and reception of signals representing data using thewireless access interface. The core network 102 may also providefunctionality including authentication, mobility management, chargingand so on for the communications devices served by the network entity.

The mobile communications devices of FIG. 2 may also be referred to ascommunications terminals, user equipment (UE), terminal devices and soforth, and are configured to communicate with one or more othercommunications devices served by the same or a different coverage areavia the network entity. These communications may be performed bytransmitting and receiving signals representing data using the wirelessaccess interface over the two way communications links.

As shown in FIG. 2, one of the eNodeBs 101 a is shown in more detail toinclude a transmitter 110 for transmitting signals via a wireless accessinterface to the one or more communications devices or UEs 104, and areceiver 112 to receive signals from the one or more UEs within thecoverage area 103. A controller 114 controls the transmitter 110 and thereceiver 112 to transmit and receive the signals via the wireless accessinterface. The controller 114 may perform a function of controlling theallocation of communications resource elements of the wireless accessinterface and may in some examples include a scheduler for schedulingtransmissions via the wireless access interface for both an uplink and adownlink.

An example UE 104 a is shown in more detail to include a transmitter 116for transmitting signals on the uplink of the wireless access interfaceto the eNodeB 101 and a receiver 118 for receiving signals transmittedby the eNodeB 101 on the downlink via the wireless access interface. Thetransmitter 116 and the receiver 118 are controlled by a controller 120.

LTE Wireless Access Interface

Mobile telecommunications systems such as those arranged in accordancewith the 3GPP defined Long Term Evolution (LTE) architecture use anorthogonal frequency division modulation (OFDM) based wireless accessinterface for the radio downlink (so-called OFDMA) and a single carrierfrequency division multiple access scheme (SC-FDMA) on the radio uplink.The down-link and the up-link of a wireless access interface accordingto an LTE standard is presented in FIGS. 3 and 4.

FIG. 3 provides a simplified schematic diagram of the structure of adownlink of a wireless access interface that may be provided by or inassociation with the eNodeB of FIG. 2 when the communications system isoperating in accordance with the LTE standard. In LTE systems thewireless access interface of the downlink from an eNodeB to a UE isbased upon an orthogonal frequency division multiplexing (OFDM) accessradio interface. In an OFDM interface the resources of the availablebandwidth are divided in frequency into a plurality of orthogonalsubcarriers and data is transmitted in parallel on a plurality oforthogonal subcarriers, where bandwidths between 1.4 MHZ and 20 MHzbandwidth may be divided into orthogonal subcarriers. Not all of thesesubcarriers are used to transmit data (some are used for features suchas the cyclic prefix of the OFDM symbols). The number of subcarriersvaries between 72 subcarriers (1.4 MHz) and 1200 subcarriers (20 MHz).In some examples the subcarriers are grouped on a basis of 2^(n), forexample 128 to 2048, so that both a transmitter and a receiver can usean inverse and a forward Fast Fourier Transform to convert thesubcarriers from the frequency domain to the time domain and from thetime domain to the frequency domain respectively. Each subcarrierbandwidth may take any value but in LTE it is fixed at 15 kHz.

As shown in FIG. 3, the resources of the wireless access interface arealso temporally divided into frames where a frame 200 lasts 10 ms and issubdivided into 10 sub-frames 201 each within a duration of 1 ms. Eachsub-frame 201 is formed from 14 OFDM symbols and is divided into twoslots 220, 222 each of which comprise six or seven OFDM symbolsdepending on whether a normal or extended cyclic prefix is beingutilised between OFDM symbols for the reduction of inter symbolinterference. The resources within a slot may be divided into resourcesblocks 203 each comprising 12 subcarriers for the duration of one slotand the resources blocks further divided into resource elements 204which span one subcarrier for one OFDM symbol, where each rectangle 204represents a resource element. The resource elements distributed in timewithin a sub-frame and frequency across the host system band widthrepresent the communications resources of the host system.

The simplified structure of the downlink of an LTE wireless accessinterface presented in FIG. 2, also includes an illustration of eachsub-frame 201, which comprises a control region 205 for the transmissionof control data, a data region 206 for the transmission of user data,reference signals 207 and synchronisation signals which are interspersedin the control and data regions in accordance with a predeterminedpattern. The control region 204 may contain a number of physicalchannels for the transmission of control data, such as a physicaldownlink control channel (PDCCH), a physical control format indicatorchannel (PCFICH) and a physical HARQ indicator channel (PHICH). The dataregion may contain a number of physical channels for the transmission ofdata or control, such as a physical downlink shared channel (PDSCH),enhanced physical downlink control channel (ePDCCH) and a physicalbroadcast channel (PBCH). Although these physical channels provide awide range of functionality to LTE systems, in terms of resourceallocation and the present disclosure ePDCCH and PDSCH are mostrelevant. Further information on the structure and functioning of thephysical channels of LTE systems can be found in [1].

Resources within the PDSCH may be allocated by an eNodeB to UEs beingserved by the eNodeB. For example, a number of resource blocks of thePDSCH may be allocated to a UE in order that it may receive data that ithad previously requested or data which is being pushed to it by theeNodeB, such as radio resource control (RRC) signalling. In FIG. 3, UE1has been allocated resources 208 of the data region 206, UE2 resources209 and UE3 resources 210. UEs in an LTE system may be allocated afraction of the available resources of the PDSCH and therefore UEs arerequired to be informed of the location of their allocated resourceswithin the PDCSH so that only relevant data within the PDSCH is detectedand estimated. In order to inform the UEs of the location of theirallocated communications resource elements, resource control informationspecifying downlink resource allocations is conveyed across the PDCCH ina form termed downlink control information (DCI), where resourceallocations for a PDSCH are communicated in a preceding PDCCH instancein the same sub-frame.

FIG. 4 provides a simplified schematic diagram of the structure of anuplink of an LTE wireless access interface that may be provided by or inassociation with the eNodeB of FIG. 2. In LTE networks the uplinkwireless access interface is based upon a single carrier frequencydivision multiplexing FDM (SC-FDM) interface and downlink and uplinkwireless access interfaces may be provided by frequency divisionduplexing (FDD) or time division duplexing (TDD), where in TDDimplementations sub-frames switch between uplink and downlink sub-framesin accordance with predefined patterns. However, regardless of the formof duplexing used, a common uplink frame structure is utilised. Thesimplified structure of FIG. 4 illustrates such an uplink frame in anFDD implementation. A frame 300 is divided in to 10 sub-frames 301 of 1ms duration where each sub-frame 301 comprises two slots 302 of 0.5 msduration. Each slot is then formed from seven OFDM symbols 303 where acyclic prefix 304 is inserted between each symbol in a manner equivalentto that in downlink sub-frames. More details of the LTE up-linkrepresented in FIG. 4 are provided in Annex 1.

Virtual Carrier

As explained above and as will be explained in the more detail in thenext section, embodiments of the present technique can provide awireless access interface in which one or more virtual RAT interfacesare provided within a host wireless access interface. In order toappreciate advantages and applications of embodiments of the presenttechnique, an explanation will now be provided in this section of ourpreviously proposed virtual carrier concept so that a betterunderstanding can be gained from the description of the exampleembodiments below.

In conventional mobile telecommunication networks, data is typicallytransmitted from the network to the mobile devices in a frequencycarrier (first frequency range) where at least part of the data spanssubstantially the whole of the bandwidth of the frequency carrier.Normally a mobile device cannot operate within the network unless it canreceive and decode data spanning the entire frequency carrier, i.e. amaximum system bandwidth defined by a given telecommunication standard,and therefore the use of mobile devices with reduced bandwidthcapability transceiver units is precluded. However, as disclosed inco-pending International patent applications numbered PCT/GB2012/050213,PCT/GB2012/050214, PCT/GB2012/050223 and PCT/GB2012/051326, the contentsof which are herein incorporated by reference, a subset of thecommunications resource elements comprising a conventional carrier (a“host carrier”) are defined as a “virtual carrier”, where the hostcarrier has a certain bandwidth (first frequency range) and where thevirtual carrier has a reduced bandwidth (second frequency range)compared to the host carrier's bandwidth. A virtual carrier can,therefore provide a facility for devices having a reduced capability orcomplexity (reduced capability devices) to receive data separatelytransmitted on the virtual carrier set of communications resourceelements. Accordingly, data transmitted on the virtual carrier can bereceived and decoded using a reduced complexity or capabilitytransceiver unit.

An example of a virtual carrier arrangement according to theabovementioned previous disclosures is presented in FIG. 5. FIG. 5represents a simplified representation of the downlink of the wirelessaccess interface shown in FIG. 3 in order to illustrate the virtualcarrier concept. Therefore the same reference numerals have been givento corresponding features of the diagram in FIG. 5 for correspondingfeatures in FIG. 3. As shown in FIG. 5, two sub-frames as shown 201which are sub-frame n and sub-frame n+1. As explained above, within eachsuccessive sub-frame within a predetermined bandwidth of the host systemthere is provided a plurality of communications resources within thehost bandwidth 500. However in accordance with the virtual carrierconcept a predetermined set of physical resources within a virtualcarrier bandwidth 502 is provided for downlink communications whentransmitting to MTC type devices. The remaining part of the physicalresources within the host carrier bandwidth 500 is available toconventional devices. In accordance with the conventional operation anyof the UE's which are transmitting and receiving data via the wirelessaccess interface can receive control channel messages via the hostcontrol region 205 which allocate communications resources within thehost downlink shared channel 510, 512, 514, 516. In contrast inaccordance with a conventional virtual carrier operation, the virtualcarrier within the reduced bandwidth 502 comprises a control channelregion 520 and a virtual downlink shared channel 522. Thus reflectingthe arrangement for the host carrier, in which control channel messagesare transmitted within the host control region 205 allocating resourceswithin the host downlink shared channel 510, 512, 514, 516 a controlmessage is transmitted within the virtual control region 520 whichallocates communications resources to the MTC devices communicating viathe virtual carrier within the virtual downlink shared channel 522.Accordingly, the virtual carrier exists within the host carrier and isdedicated for communicating data to reduced capability or MTC typedevices via a reduced bandwidth 502.

FIG. 6 provides an example in which there is no dedicated virtualcontrol region 520 such as that shown in FIG. 5 but the allocation ofcommunications resources within a virtual carrier 502 is provided bycommunicating control messages via the conventional host control channelregion 205. Thus as shown by arrow 540 a control channel messagereceived from the PDCCH in the host control channel region 205 canallocate to an MTC type UE communications resources within the virtualcarrier 502 across the sub-frame 201. Thus the communications resourcesof the shared channel in the darker shaded region 542 are allocated toone of the MTC UE's for receiving downlink communications. Thisarrangement is a so-called T shaped allocation of communicationsresources.

Improved Wireless Access Interface

According to the present technique one or more virtual radio accesstechnology (RAT) interfaces is provided within a host wireless accessinterface in which different communications parameters are provided bythe wireless access interface for transmitting and receiving signals.Accordingly, there can be a reserved subset of resources within anarrower bandwidth within the host bandwidth. The virtual RAT interfaceis configurable and may differ to both the host bandwidth and to avirtual carrier as described above in accordance with a number ofcommunications parameters, including but not limited to the following:

-   -   TTI length    -   Sub-frame length    -   Physical resource block bandwidth    -   Resource element/resource block size    -   Modulation scheme    -   Subcarrier spacing    -   Symbol duration    -   Waveform (e.g. GDFMA, single carrier FDMA, OFDMA)

Example embodiments find application with a 5G system, in which aflexible and dynamic allocation of the communications resources of thewireless access interface can be provided, without precondition on anexisting wireless access interface. However some of the aspects couldfeasibly be implemented using an LTE wireless access interface asdescribed above such as for example a variable TTI length as explainedbelow.

According to the present technique there is provided an arrangement inwhich a mobile communications network provides a wireless accessinterface in which host communications resources are divided into aplurality of different regions which may provide communicationsresources in accordance with, for example, a different sub-framestructure and allocation of frequency resources which may provide for adifferent modulation scheme, a different waveform, or a different subcarrier spacing, modulation symbol duration. An example of such anarrangement is shown in FIG. 7. As shown in FIG. 7 the host wirelessaccess interface comprises in accordance with the arrangement shown inFIGS. 5 and 6 a host control channel region 205 in each of 4 sub-frames201. Also shown in FIG. 7 in correspondence with the arrangement shownin FIG. 6 a virtual RAT interface region is provided within a restrictedbandwidth 502. However according to the present technique thearrangement shown in FIG. 7 provides a virtual RAT sub-frame structurecomprising all four of the sub-frames of the host system. According tothe present technique therefore, a first of the sub-frames 700 is usedto transmit control messages within the virtual RAT interface region 702for allocating the communications resources within the remainingsub-frames 704, 706, 708 within the virtual RAT interface region 710,712, 714. According to this arrangement a sub-frame transmission basisthen represents 4 times the sub-frame period of the host system. Assuch, the allocation of communications resources from the wirelessaccess interface to particular types of devices is then performed over alonger period and would therefore suit applications which do not requirea short latency. The more lenient latency requirement may allow for lesscomplex devices to be designed.

As long as the TTI length is a multiple (2, 4, 8, etc) of the host TTIlength, then it is quite simple for these different systems to co-existwithin the same system. In the example above the virtual control regionoccupies the first host system sub-frame 702, and the data regionoccupies the following three sub-frames, 710, 712, 714, making thevirtual sub-frame length of 4 ms (assuming 1 ms LTE TTI). This wouldallow for higher latency and lower complexity devices.

A corresponding arrangement in reverse is shown in FIG. 8, which uses ashorter TTI length within the host bandwidth/resources. According to thearrangement shown in FIG. 8, a host RAT interface bandwidth 500 isarranged to use enhanced physical downlink control channel regions(ePDCCH) 800, 802 spanning the length of the sub-frame in the highestand lowest frequency locations of the host RAT interface bandwidth 500,but in 5G there are other possibilities, for example to have controlinformation in any physical resource location.

The arrangement shown in FIG. 8 comprises a single sub-frame 804 of thehost wireless access interface. However, within a virtual RAT interfaceregion of frequencies 502, the communications resources are divided intointeger fractions to produce virtual sub-frames 810, 812, 814, 816.Within each of the virtual RAT sub-frames, the communications resourceswithin the frequency bandwidth are divided into a virtual control region820 and a shared data resource region 822, also termed a virtual dataregion. According to the present technique therefore control channelmessages allocating communications resources within the virtual dataregion 822 are transmitted within the virtual control region 820 whichallocate resources within the virtual sub-frames 810, 812, 814, 816.Accordingly, the allocation of communications resources within thevirtual RAT interface region 502 is performed over a much shorter periodbeing an integer fraction of the sub-frame duration of the host RATinterface. Accordingly, data can be transmitted to support servicesrequiring a much shorter latency than is available from the host RATinterface.

The virtual control regions 820 of the virtual RAT 502 are shown asoccupying the full bandwidth and a limited time duration of the virtualRAT. This is merely an example, and the virtual control region couldinstead have a different structure, such as an ePDCCH-like structure,whereby the virtual control region occupies a limited amount offrequency resource, but the full time duration of the virtual sub-frames810, 812, 814, 816.

According to some embodiments, one or more control regions of thevirtual RAT sub-frames can be used to indicate to the UEs wheredifferent waveforms are being applied in the host RAT interface. Forexample, virtual sub-frame n+3 816 (FIG. 8) could indicate whichfrequency resources are being used for a low latency waveform and whichsub-frames are being used for a higher latency waveform in the following“m” host RAT interface sub-frames. If the UEs have this information,they do not have to attempt to decode frequency resources in sub-framesthat have a non-compatible numerology, thereby saving battery resourcesand do not make unnecessary and meaningless measurements on frequencieswith non-compatible numerologies.

When the virtual RAT interface TTI length is a multiple of the host RATinterface TTI length (or an integer fraction of the host RAT interfaceTTI length), the virtual RAT interface regions can be frequency hopped,allowing frequency diversity gain to be achieved. For example, ifvirtual RAT interface A has a TTI length of 4 times that of the host RATinterface (a higher latency VC) and if virtual RAT interface B has a TTIlength of half that of the host RAT interface (a lower latency VC), thenvirtual RAT interfaces can be hopped every 4 sub-frames of the host RATinterface. In this case:

-   -   virtual RAT interface A would use the same frequency resources        for 1 “virtual RAT interface A” TTI=4 host RAT interface TTIs        and then hop;    -   virtual RAT interface B would use the same frequency resources        for 8 “virtual RAT interface B” TTI=4 host RAT interface TTIs        and then hop.

According to the present technique a subset of the physical resourcesare configured to be used with a different set of communicationsparameters, such as for example a different TTI/sub-frame length, adifferent physical resource element or resource block size, a differentPRB bandwidth, a different subcarrier spacing, a different modulationsymbol duration or a configuration of control/data channel structure maybe different. For example, as shown in FIG. 8 the virtual RAT interfaceuses a control channel structure more similar to LTE PDCCH, while thehost RAT interface uses a structure more similar to ePDCCH. In the caseof 5G, a different waveform (e.g. Generalised Frequency DivisionMultiplexing, GFDM) could be used in the virtual RAT interface, allowingfor higher spectral efficiency, shorter TTI, lower latency, etc. When adifferent waveform is used in the virtual RAT interface, a guard bandmay be inserted between the virtual RAT interface and the host RATinterface. This guard band may consist of a group of subcarriers toprovide frequency isolation between the virtual RAT interface and thehost RAT interface. The guard band may instead/in addition consist of anidle time between the virtual RAT interface region and the host RATinterface region, which is to provide some time domain isolation betweenthe virtual RAT interface and host RAT interface, allowing inter-symbolinterference between the virtual and host RAT interfaces to becontrolled.

FIG. 9 provides a further example embodiment of the present technique inwhich two different virtual RAT interfaces 900, 902 are provided withina host wireless access interface 500 configured in accordance with anLTE Standard as for the example illustrated in FIGS. 3, 7 and 8. As forthe example illustration shown in FIG. 3, the resource elements 204 ofthe host wireless access interface 500 are divided into the PDCCH 205and the PDSCH 206. However, as shown in FIG. 9, a first virtual RATinterface 900 is provided within the communications resources of thehost wireless access system 500. A second virtual RAT interface is alsoprovided 902. However the physical resource blocks of the first virtualRAT interface 900 are different to the physical resource blocks of thesecond virtual RAT interface 902. The first virtual RAT interface isprovided across the entire sub-frame interval 201 and may comprise adifferent waveform and therefore a different configuration in time andfrequency of the resource elements 910 which therefore have a differentspacing with respect to the resource elements of the host wirelessaccess interface. As shown in FIG. 9, the resource elements 910 of thefirst virtual RAT interface 900 have a shorter time duration and widersubcarrier spacing than the resource elements 204 of the host wirelessaccess interface. Furthermore, the first virtual RAT interface includesa guard frequency band comprising higher frequencies 912 with respect tothe virtual RAT interface resource elements 910 and a guard bandcomprising lower frequencies 914. There is also included a guard time ofa duration comprising a non-integer multiple of the time duration of theresource elements of the host wireless access interface 916, 918. Incontrast the second virtual RAT interface provides resource elements ofa larger duration 920 and includes a time guard time 922.

FIG. 10 provides a further example embodiment of the present techniquein which two different virtual RAT interfaces 1000, 1002 are providedwithin a host wireless access interface 500 configured in accordancewith an LTE Standard as for the example illustrated in FIGS. 3, 7 and 8.As shown in FIG. 10, communications resource elements of the hostwireless access interface 500 are divided into the shared resources 1004and upper and lower host control channel regions 800, 802. However, asshown in FIG. 10, a first virtual RAT interface 1000 is provided withinthe communications resources of the host wireless access system 500. Asecond virtual RAT interface is also provided 1002. However the physicalresource blocks of the first virtual RAT interface 1000 are different tothe physical resource blocks of the second virtual RAT interface 1002.The first virtual RAT interface is provided in one section across two ofsub-frame intervals 1006 and may comprise a different waveform andtherefore a different configuration in time and frequency of theresource elements, which therefore have a different spacing, withrespect to the resource elements of the host wireless access interface.The first virtual RAT may also have a much shorter virtual RAT sub-frameduration 1010.

FIG. 10 therefore provides an illustration of different communicationsparameters provided within different virtual RAT interfaces within ahost wireless access interface. FIG. 10 therefore illustrates thataccording to the present technique, different sized resource elementsand physical resource blocks can be provided for different applications.FIG. 10 therefore illustrates the following aspects:

-   -   A host RAT interface 500, which (even though it is a 5G carrier)        might have an LTE Release-12-like structure and numerology        (including subcarrier spacing, symbol duration, number of        symbols per subframe, cyclic prefix duration, etc.)        -   The host RAT interface 500 shown has an ePDCCH-like            structure for the control channels 800, 802        -   The host RAT interface has a 1 ms subframe duration,            consisting of 14 OFDM symbols, with a subcarrier spacing of            15 kHz    -   The Virtual RAT1 1000 (e.g. a low latency, high data rate        virtual RAT), has the following features:        -   Subframe duration 0.25 ms (25% that of the host RAT)        -   Signal structure is GFDM            -   subcarrier spacing=60 kHz            -   GFDM symbol duration=LTE symbol duration divided by four        -   Only allocated in subframes ‘n’ and ‘n+1’ of the illustrated            host RAT's subframe structure    -   The Virtual RAT2 1002 (e.g. a higher latency, long range        coverage virtual RAT for MTC applications) has the following        features:        -   Subframe duration is 2 ms (200% that of the host RAT)        -   Signal structure consists of multiple narrowband carriers            (filter multibank)            -   Narrowband carrier spacing=1 kHz            -   GMSK modulation            -   Longer symbol duration than host RAT        -   Different control channel structure to the host RAT. Virtual            RAT2 uses a time division control channel structure (in the            same way that the PDCCH is a time domain control channel            structure)        -   Only allocated in some subframes of the host RAT    -   When the virtual RATs are not active, resources can be used by        the host RAT

As illustrated above, within the host bandwidth, a number of differentvirtual RAT interfaces could co-exist, each with differentparameterisation for use with different types of service. For example along TTI with low data rate for MTC devices, an intermediate TTI with anaverage latency and throughput for smartphones, and a short TTI with lowlatency for time-critical applications such as tactile internet devicesor virtual reality headsets. Different virtual RAT interfaces couldpotentially be provided by different network nodes, for example avirtual RAT interface for use with a femto cell could share the samephysical spectrum as the macro cell.

There are various options for configuration, ranging from use of fixedconfigurations, broadcast configurations, and configurations signalledindividually to a device, while the overall resource management is donein the network.

Various modifications can be made to examples of the present disclosure.

Various further aspects and features of the present invention aredefined in the following numbered clauses:

REFERENCES

-   [1] LTE for UMTS: OFDMA and SC-FDMA Based Radio Access, Harris Holma    and Antti Toskala, Wiley 2009, ISBN 978-0-470-99401-6.-   [2] 4G Americas, “4G Americas' Recommendations on 5G Requirements    and Solutions,” October 2014.-   [3] Ericsson, “Ericsson Mobility Report on the Pulse of the    Networked Society,” November 2014.

ANNEX 1

As shown in FIG. 4, each LTE uplink sub-frame may include a plurality ofdifferent channels, for example a physical uplink communications channel(PUSCH) 305, a physical uplink control channel (PUCCH) 306, and aphysical random access channel (PRACH). The physical Uplink ControlChannel (PUCCH) may carry control information such as ACK/NACK to theeNodeB for downlink transmissions, scheduling request indicators (SRI)for UEs wishing to be scheduled uplink resources, and feedback ofdownlink channel state information (CSI) for example. The PUSCH maycarry UE uplink data or some uplink control data. Resources of the PUSCHare granted via PDCCH, such a grant being typically triggered bycommunicating to the network the amount of data ready to be transmittedin a buffer at the UE. The PRACH may be scheduled in any of theresources of an uplink frame in accordance with a one of a plurality ofPRACH patterns that may be signalled to UE in downlink signalling suchas system information blocks. As well as physical uplink channels,uplink sub-frames may also include reference signals. For example,demodulation reference signals (DMRS) 307 and sounding reference signals(SRS) 308 may be present in an uplink sub-frame where the DMRS occupythe fourth symbol of a slot in which PUSCH is transmitted and are usedfor decoding of PUCCH and PUSCH data, and where SRS are used for uplinkchannel estimation at the eNodeB. The ePDCCH channel carries similarcontrol information (DCI) as the PDCCH, but the physical aspects ofPDCCH are different to those of ePDCCH, as discussed elsewhere herein.Further information on the structure and functioning of the physicalchannels of LTE systems can be found in [1].

In an analogous manner to the resources of the PDSCH, resources of thePUSCH are required to be scheduled or granted by the serving eNodeB andthus if data is to be transmitted by a UE, resources of the PUSCH arerequired to be granted to the UE by the eNodeB. At a UE, PUSCH resourceallocation is achieved by the transmission of a scheduling request or abuffer status report to its serving eNodeB. The scheduling request maybe made, when there is insufficient uplink resource for the UE to send abuffer status report, via the transmission of Uplink Control Information(UCI) on the PUCCH when there is no existing PUSCH allocation for theUE, or by transmission directly on the PUSCH when there is an existingPUSCH allocation for the UE. In response to a scheduling request, theeNodeB is configured to allocate a portion of the PUSCH resource to therequesting UE sufficient for transferring a buffer status report andthen inform the UE of the buffer status report resource allocation via aDCI in the PDCCH. Once or if the UE has PUSCH resource adequate to senda buffer status report, the buffer status report is sent to the eNodeBand gives the eNodeB information regarding the amount of data in anuplink buffer or buffers at the UE. After receiving the buffer statusreport, the eNodeB can allocate a portion of the PUSCH resources to thesending UE in order to transmit some of its buffered uplink data andthen inform the UE of the resource allocation via a DCI in the PDCCH.For example, presuming a UE has a connection with the eNodeB, the UEwill first transmit a PUSCH resource request in the PUCCH in the form ofa UCI. The UE will then monitor the PDCCH for an appropriate DCI,extract the details of the PUSCH resource allocation, and transmituplink data, at first comprising a buffer status report, and/or latercomprising a portion of the buffered data, in the allocated resources.

Although similar in structure to downlink sub-frames, uplink sub-frameshave a different control structure to downlink sub-frames, in particularthe upper 309 and lower 310 subcarriers/frequencies/resource blocks ofan uplink sub-frame are reserved for control signaling rather than theinitial symbols of a downlink sub-frame. Furthermore, although theresource allocation procedure for the downlink and uplink are relativelysimilar, the actual structure of the resources that may be allocated mayvary due to the different characteristics of the OFDM and SC-FDMinterfaces that are used in the downlink and uplink respectively. InOFDM each subcarrier is individually modulated and therefore it is notnecessary that frequency/subcarrier allocation are contiguous however,in SC-FDM subcarriers are modulated in combination and therefore ifefficient use of the available resources are to be made contiguousfrequency allocations for each UE are preferable.

Embodiments of the disclosure may be generally described in thefollowing numbered paragraphs.

Paragraph 1. A communications device for transmitting data to orreceiving data from a wireless communications network, thecommunications device comprising:

-   -   a transmitter configured to transmit signals to one or more        infrastructure equipment of the wireless communications network        via a wireless access interface,    -   a receiver configured to receive signals from one or more of the        infrastructure equipment of the wireless communications network        via the wireless access interface, and    -   a controller configured to control the transmitter and the        receiver to transmit the signals and to receiver the signals via        the wireless access interface, wherein the wireless access        interface provides communications resources arranged in time        divided units of a host radio access technology, RAT, frequency        bandwidth, the time divided units and the host RAT interface        frequency bandwidth being arranged into one or more virtual RAT        interfaces, and the receiver is configured to receive the        signals being transmitted via one of the virtual RAT interfaces        in accordance with different communications parameters from the        host RAT interface providing different characteristics for        communicating data represented by the signals with respect to a        characteristic of signals transmitted according to        communications parameters in the communications resources of the        host RAT interface.

Paragraph 2. A communications device as claimed in paragraph 1, whereinthe time divided units of the host RAT interface are time frames, eachtime frame comprising a plurality of sub-frames, and one of the virtualRAT interfaces comprises communications resources within a virtual RATinterface bandwidth, which is less than the host RAT interfacebandwidth, and the virtual RAT interface bandwidth is divided into aplurality of time divided frames, each frame including a plurality ofsub-frames, the receiver being configured with the controller to receivefrom the one or more infrastructure equipment an allocation of thecommunications resources of the shared channel, and each of thesub-frames of the virtual RAT interface comprises a plurality of thesub-frames of the host RAT interface within the virtual RAT interfacebandwidth, the sub-frame of the virtual RAT interface is longer than thesub-frame of the host RAT interface so that a communications parameterdefining a time for receiving data from the one or more infrastructureequipment is longer than for the host RAT interface.

Paragraph 3. A communications channel as claimed in paragraph 2, whereinthe sub-frame of the virtual RAT interface is equal to m sub-frames ofthe host RAT interface.

Paragraph 4. A communications device as claimed in paragraph 2 or 3,wherein each of the sub-frames of the virtual RAT interface includes acontrol channel region and a shared channel region, the control channelregion has a temporal length equal to at least one of the sub-frames ofthe host RAT interface and the shared channel region has a temporallength equal to a plurality of the sub-frames of the host RAT interface.

Paragraph 5. A communications device as claimed in paragraph 1, whereinthe time divided units of the host RAT interface are time frames, eachtime frame comprising a plurality of sub-frames, and one of the virtualRAT interfaces comprises communications resources within a virtual RATinterface bandwidth, which is less than the host RAT interfacebandwidth, and the virtual RAT interface bandwidth is divided into aplurality of time divided frames, each frame including a plurality ofsub-frames, and a temporal length of each of the sub-frames of thevirtual RAT interface is arranged so that a temporal length of each ofthe sub-frames of the host RAT interface is equal to a plurality of thesub-frames of the virtual RAT interface, the sub-frame of the virtualRAT interface being shorter than the sub-frame of the host RAT interfaceso that a communications parameter defining a time for receiving datafrom the one or more infrastructure equipment is shorter than for thehost RAT interface.

Paragraph 6. A communications channel as claimed in paragraph 1, whereinthe sub-frame of the virtual RAT interface is equal to an integerfraction 1/m of the temporal length of the host RAT interface, m beingan integer.

Paragraph 7. A communications device as claimed in paragraph 5 or 6,wherein each of the sub-frames includes a control channel region and ashared channel region, and the receiver is configured with thecontroller to receive the control channel messages from the one or moreinfrastructure equipment providing an allocation of the communicationsresources of the shared channel, the control channel region and theshared channel region have a temporal length which is less than one ofthe sub-frames of the host RAT interface.

Paragraph 8. A communications device as claimed in any of paragraphs 1to 7, wherein one of the communications parameters is a waveform of thesignals which is used to transmit the data via a virtual RAT interface,and one of the virtual RAT interfaces is arranged with a differentwaveform to a waveform which is used to transmit the signals on the hostRAT interface frequency resources.

Paragraph 9. A communications device as claimed in any of paragraphs 1to 7, wherein one of the communications parameters is a configuration ofa physical resource element in time or frequency, which is used totransmit the data via a virtual RAT interface, and one of the virtualRAT interfaces is configured with a differently dimensioned physicalresource element in time or frequency to the dimensions of the physicalresource elements of the host RAT interface.

Paragraph 10. A communications device as claimed in paragraph 8 or 9,wherein the virtual RAT interface includes a guard band comprisingcommunications resources in the frequency domain of the host RATinterface in which signals of neither the host RAT interface nor thevirtual RAT interface are transmitted, wherein signals received withinthe communications resources of the guard band may be discarded.

Paragraph 11. A communications device as claimed in paragraph 8 or 9,wherein the virtual RAT interface includes a guard time comprisingcommunications resources of the host RAT interface in the time domain inwhich signals of neither the host RAT interface nor the virtual RATinterface are transmitted, wherein signals received within thecommunications resources of the guard band may be discarded.

Paragraph 12. A communications device as claimed in any of paragraphs 1to 11, wherein the communications parameters of the virtual RATinterface are configured dynamically, and the receiver in combinationwith the controller is configured to receive an indication of thecommunications resources of the virtual RAT interface.

Paragraph 13. A communications device for transmitting data to orreceiving data from a mobile communications network, the communicationsdevice comprising:

-   -   a transmitter configured to transmit signals to one or more        infrastructure equipment of the wireless communications network        via a wireless access interface,    -   a receiver configured to receive signals from one or more of the        infrastructure equipment of the wireless communications network        via the wireless access interface, and    -   a controller configured to control the transmitter and the        receiver to transmit the signals and to receive the signals via        the wireless access interface, wherein the wireless access        interface is configured to allocate physical communications        resources to provide different radio access techniques to        different types of devices, the different radio access        techniques providing different virtual RAT interfaces comprising        different communications parameters for different types of        communications for different communications devices.

Paragraph 14. An infrastructure equipment for transmitting data tocommunications devices or receiving data from communications deviceswithin a wireless communications network, the infrastructure equipmentcomprising:

-   -   a transmitter configured to transmit signals to one or more of        the communications devices via a wireless access interface,    -   a receiver configured to receive signals from the one or more of        the communications devices via the wireless access interface,        and    -   a controller configured to control the transmitter and the        receiver to transmit the signals and to receive the signals via        the wireless access interface, wherein the controller is        configure to control the transmitter to form the wireless access        interface providing communications resources arranged in time        divided units of a host radio access technology, RAT, interface        frequency bandwidth, the time divided units and the host RAT        interface frequency bandwidth being arranged into one or more        virtual RAT interfaces, and the transmitter is configured to        transmit the signals via one of the virtual RAT interfaces in        accordance with different communications parameters from the        host RAT interface providing different characteristics for        communicating data represented by the signals with respect to a        characteristic of signals transmitted according to        communications parameters in the communications resources of the        host RAT interface for communicating data in accordance with        different characteristics to those of the host RAT interface.

Paragraph 15. A method of communicating data to a communications devicevia a wireless communications network, the method comprising:

-   -   receiving signals from one or more of the infrastructure        equipment of the wireless communications network via the        wireless access interface, the wireless access interface        providing communications resources arranged in time divided        units of a host radio access technology, RAT, frequency        bandwidth, the time divided units and the host RAT interface        frequency bandwidth being arranged into one or more virtual RAT        interfaces, and the receiving comprises selecting one of the        virtual RAT interfaces, and    -   receiving the signals transmitted via the virtual RAT interface        in accordance with different    -   communications parameters from the host RAT interface providing        different characteristics for communicating data represented by        the signals with respect to a characteristic of signals        transmitted according to communications parameters in the        communications resources of the host RAT interface.

Paragraph 16. A method of communicating data to one or morecommunications devices from an infrastructure equipment of a wirelesscommunications network, the method comprising

-   -   transmitting signals to one or more of the communications        devices via a wireless access interface, the wireless access        interface providing communications resources arranged in time        divided units of a host radio access technology, RAT, frequency        bandwidth, the time divided units and the host RAT interface        frequency bandwidth being arranged into one or more virtual RAT        interfaces, and the transmitting includes    -   transmitting signals via one or more of the virtual RAT        interfaces to one or more of the communications devices in        accordance with different communications parameters from the        host RAT interface providing different characteristics for        communicating data represented by the signals with respect to a        characteristic of signals transmitted according to        communications parameters in the communications resources of the        host RAT interface for communicating data in accordance with        different characteristics to those of the host RAT interface.

1. A communications device for transmitting data to or receiving datafrom a wireless communications network, the communications devicecomprising: a transmitter configured to transmit signals to one or moreinfrastructure equipment of the wireless communications network via awireless access interface, a receiver configured to receive signals fromone or more of the infrastructure equipment of the wirelesscommunications network via the wireless access interface, and acontroller configured to control the transmitter and the receiver totransmit the signals and to receiver the signals via the wireless accessinterface, wherein the wireless access interface provides communicationsresources arranged in time divided units of a host radio accesstechnology, RAT, frequency bandwidth, the time divided units and thehost RAT interface frequency bandwidth being arranged into one or morevirtual RAT interfaces, and the receiver is configured to receive thesignals being transmitted via one of the virtual RAT interfaces inaccordance with different communications parameters from the host RATinterface providing different characteristics for communicating datarepresented by the signals with respect to a characteristic of signalstransmitted according to communications parameters in the communicationsresources of the host RAT interface.
 2. A communications device asclaimed in claim 1, wherein the time divided units of the host RATinterface are time frames, each time frame comprising a plurality ofsub-frames, and one of the virtual RAT interfaces comprisescommunications resources within a virtual RAT interface bandwidth, whichis less than the host RAT interface bandwidth, and the virtual RATinterface bandwidth is divided into a plurality of time divided frames,each frame including a plurality of sub-frames, the receiver beingconfigured with the controller to receive from the one or moreinfrastructure equipment an allocation of the communications resourcesof the shared channel, and each of the sub-frames of the virtual RATinterface comprises a plurality of the sub-frames of the host RATinterface within the virtual RAT interface bandwidth, the sub-frame ofthe virtual RAT interface is longer than the sub-frame of the host RATinterface so that a communications parameter defining a time forreceiving data from the one or more infrastructure equipment is longerthan for the host RAT interface.
 3. A communications channel as claimedin claim 2, wherein the sub-frame of the virtual RAT interface is equalto m sub-frames of the host RAT interface.
 4. A communications device asclaimed in claim 2, wherein each of the sub-frames of the virtual RATinterface includes a control channel region and a shared channel region,the control channel region has a temporal length equal to at least oneof the sub-frames of the host RAT interface and the shared channelregion has a temporal length equal to a plurality of the sub-frames ofthe host RAT interface.
 5. A communications device as claimed in claim1, wherein the time divided units of the host RAT interface are timeframes, each time frame comprising a plurality of sub-frames, and one ofthe virtual RAT interfaces comprises communications resources within avirtual RAT interface bandwidth, which is less than the host RATinterface bandwidth, and the virtual RAT interface bandwidth is dividedinto a plurality of time divided frames, each frame including aplurality of sub-frames, and a temporal length of each of the sub-framesof the virtual RAT interface is arranged so that a temporal length ofeach of the sub-frames of the host RAT interface is equal to a pluralityof the sub-frames of the virtual RAT interface, the sub-frame of thevirtual RAT interface being shorter than the sub-frame of the host RATinterface so that a communications parameter defining a time forreceiving data from the one or more infrastructure equipment is shorterthan for the host RAT interface.
 6. A communications channel as claimedin claim 1, wherein the sub-frame of the virtual RAT interface is equalto an integer fraction 1/m of the temporal length of the host RATinterface, m being an integer.
 7. A communications device as claimed inclaim 5, wherein each of the sub-frames includes a control channelregion and a shared channel region, and the receiver is configured withthe controller to receive the control channel messages from the one ormore infrastructure equipment providing an allocation of thecommunications resources of the shared channel, the control channelregion and the shared channel region have a temporal length which isless than one of the sub-frames of the host RAT interface.
 8. Acommunications device as claimed in claim 1, wherein one of thecommunications parameters is a waveform of the signals which is used totransmit the data via a virtual RAT interface, and one of the virtualRAT interfaces is arranged with a different waveform to a waveform whichis used to transmit the signals on the host RAT interface frequencyresources.
 9. A communications device as claimed in claim 1, wherein oneof the communications parameters is a configuration of a physicalresource element in time or frequency, which is used to transmit thedata via a virtual RAT interface, and one of the virtual RAT interfacesis configured with a differently dimensioned physical resource elementin time or frequency to the dimensions of the physical resource elementsof the host RAT interface.
 10. A communications device as claimed inclaim 8, wherein the virtual RAT interface includes a guard bandcomprising communications resources in the frequency domain of the hostRAT interface in which signals of neither the host RAT interface nor thevirtual RAT interface are transmitted, wherein signals received withinthe communications resources of the guard band may be discarded.
 11. Acommunications device as claimed in claim 8, wherein the virtual RATinterface includes a guard time comprising communications resources ofthe host RAT interface in the time domain in which signals of neitherthe host RAT interface nor the virtual RAT interface are transmitted,wherein signals received within the communications resources of theguard band may be discarded.
 12. A communications device as claimed inclaim 1, wherein the communications parameters of the virtual RATinterface are configured dynamically, and the receiver in combinationwith the controller is configured to receive an indication of thecommunications resources of the virtual RAT interface.
 13. Acommunications device for transmitting data to or receiving data from amobile communications network, the communications device comprising: atransmitter configured to transmit signals to one or more infrastructureequipment of the wireless communications network via a wireless accessinterface, a receiver configured to receive signals from one or more ofthe infrastructure equipment of the wireless communications network viathe wireless access interface, and a controller configured to controlthe transmitter and the receiver to transmit the signals and to receivethe signals via the wireless access interface, wherein the wirelessaccess interface is configured to allocate physical communicationsresources to provide different radio access techniques to differenttypes of devices, the different radio access techniques providingdifferent virtual RAT interfaces comprising different communicationsparameters for different types of communications for differentcommunications devices.
 14. (canceled)
 15. A method of communicatingdata to a communications device via a wireless communications network,the method comprising: receiving signals from one or more of theinfrastructure equipment of the wireless communications network via thewireless access interface, the wireless access interface providingcommunications resources arranged in time divided units of a host radioaccess technology, RAT, frequency bandwidth, the time divided units andthe host RAT interface frequency bandwidth being arranged into one ormore virtual RAT interfaces, and the receiving comprises selecting oneof the virtual RAT interfaces, and receiving the signals transmitted viathe virtual RAT interface in accordance with different communicationsparameters from the host RAT interface providing differentcharacteristics for communicating data represented by the signals withrespect to a characteristic of signals transmitted according tocommunications parameters in the communications resources of the hostRAT interface.
 16. (canceled)